//
//  LWXCycleView.m
//  CycleScrollViewDemo
//
//  Created by lanou3g on 16/4/19.
//  Copyright © 2016年 Liuwx. All rights reserved.
//

#import "LWXCycleView.h"

@interface LWXCycleView()<UIScrollViewDelegate>

// scrollView
@property (nonatomic, strong) UIScrollView *imgScrollView;

//pageControl
@property (nonatomic, strong) UIPageControl *imgPageControl;

//imageViewArray
@property (nonatomic, strong) NSMutableArray *imgViewArray;

// 存方图片的数组
@property (nonatomic, strong) NSMutableArray *imgArray;

// 当前展示的图片下标
@property (nonatomic, assign) NSInteger index;

//定时器
@property (nonatomic, strong) NSTimer *imgTimer;

//点击回调 block
@property (nonatomic, copy) void(^tapBlock)(NSInteger index);
//设置时间间隔
@property (nonatomic, assign) NSTimeInterval interval;

@end
@implementation LWXCycleView

// 初始化方法
- (instancetype)initWithFrame:(CGRect)frame interVal:(NSTimeInterval)interval {
    
    self = [super initWithFrame:frame];
    
    if (self) {
        self.imgViewArray = [NSMutableArray new];
        self.imgArray     = [NSMutableArray new];
        self.imgScrollView = [[UIScrollView alloc] initWithFrame:self.bounds];
        self.imgScrollView.contentSize = CGSizeMake(frame.size.width * 3, frame.size.height);
        [self addSubview:self.imgScrollView];
        for (int i = 0; i < 3; i++) {
            UIImageView *imgView = [[UIImageView alloc]initWithFrame:CGRectMake(frame.size.width * i, 0, frame.size.width, frame.size.height)];
            //添加到父视图 数组
            [self.imgScrollView addSubview:imgView];
            [self.imgViewArray addObject:imgView];
         }
        self.interval = interval;
        
            self.imgScrollView.pagingEnabled = YES;
            self.imgScrollView.showsHorizontalScrollIndicator = NO;
            self.imgScrollView.delegate = self;

    }

    return self;
}

//图片滚动的方法

- (void)timerAction {
    [self.imgScrollView setContentOffset:CGPointMake(self.imgScrollView.frame.size.width * 2, 0) animated:YES];
    // 改变 index
    self.index = (self.index + 1) % self.imgNameArray.count;

}

- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView{
    //回原位置不带动画
    [self.imgScrollView setContentOffset:CGPointMake(scrollView.frame.size.width, 0) animated:NO];
    [self layoutImages];
}


// 图片名数组 setter
- (void)setImgNameArray:(NSMutableArray *)imgNameArray {
    if (_imgNameArray != imgNameArray) {
        _imgNameArray = imgNameArray;
        [self.imgPageControl removeFromSuperview];
        self.imgPageControl = [[UIPageControl alloc]initWithFrame:CGRectMake(0, self.frame.size.height - 40, self.frame.size.width, 40)];
        [self addSubview:self.imgPageControl];
        //属性
        self.imgPageControl.currentPage = 0;
        self.imgPageControl.numberOfPages = _imgNameArray.count;
        
        //关闭响应
        self.imgPageControl.enabled = NO;
        
        for (int i = 0; i < imgNameArray.count; i++) {
//            UIImage *img = [UIImage imageWithData:[NSData dataWithContentsOfURL:[NSURL URLWithString:imgNameArray[i]]]];
            UIImage *img = [UIImage imageNamed:imgNameArray[i]];
         
            [self.imgArray addObject:img];
            if (i < 3) {
                [self.imgViewArray[i] setImage:img];
            }
        }
        
        //设置当前偏移量
        [self.imgScrollView setContentOffset:CGPointMake(self.frame.size.width, 0) animated:NO];
         self.index = 0;
        [self layoutImages];
        
        //点击手势
        UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc]initWithTarget:self action:@selector(tapCycleViewAction:)];
        [(UIImageView *)self.imgViewArray[1] addGestureRecognizer:tap];
        // 打开交互 imageView 和 label 是默认关闭的所以要打开
        [(UIImageView *)self.imgViewArray[1] setUserInteractionEnabled:YES];
        
        //初始化 timer
        if (self.interval <= 0) {
            self.imgTimer = [NSTimer scheduledTimerWithTimeInterval:3 target:self selector:@selector(timerAction) userInfo:nil repeats:YES];
            
        }else {
            self.imgTimer = [NSTimer scheduledTimerWithTimeInterval:self.interval target:self selector:@selector(timerAction) userInfo:nil repeats:YES];
        }
        
    }
}
//手势的点击事件
- (void)tapCycleViewAction:(UITapGestureRecognizer *)tap {
    if (self.tapBlock) {
        self.tapBlock(self.index);
    }
}

#pragma mark - UiScrollViewDelegate
//开始拖拽
static CGFloat x = 0;
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView {
    x = scrollView.contentOffset.x;
    
    //这个是释放 timer 不能用这个方法  [self.imgTimer invalidate];
    //未来的时间（distantFuture）触发
    [self.imgTimer setFireDate:[NSDate distantFuture]];

   }
// 减速动画结束
- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView {
    if (x > scrollView.contentOffset.x) {
        [self panToLeft:NO Index:self.index];
    }else if (x < scrollView.contentOffset.x) {
        
        [self panToLeft:YES Index:self.index];
    }
    //拖拽的时候一松手就开始启动定时器了 [self.imgTimer setFireDate:[NSDate date]];
    
    [self.imgTimer setFireDate:[NSDate dateWithTimeIntervalSinceNow:3]];
    
}

#pragma mark - 向左滑动， 向右滑动结束切换

- (void)panToLeft:(BOOL)left Index:(NSInteger)index {
    
      if (!left) {
          self.index = (index - 1 + self.imgNameArray.count) % self.imgNameArray.count;
         
    }else {
        self.index = (index + 1) % self.imgNameArray.count;
            }
    //切换图片
    [self layoutImages];
    //回位操作               显示中间的一张
    [self.imgScrollView setContentOffset:CGPointMake(self.frame.size.width, 0) animated:NO];
  
    
    
}

- (void)layoutImages {
    for (int i = 0 ; i < 3; i++) {
        [self.imgViewArray[i] setImage:self.imgArray[(self.index - 1 + i + self.imgNameArray.count) % self.imgNameArray.count]];
        
    }
}

// index 的 setter 方法

- (void)setIndex:(NSInteger)index {
    if (_index != index) {
        _index = index;
        self.imgPageControl.currentPage = index;
    }
}

// 添加 Block 回调
- (void)addTapBlock:(void(^)(NSInteger index))block {
    self.tapBlock = block;
}

/*
// Only override drawRect: if you perform custom drawing.
// An empty implementation adversely affects performance during animation.
- (void)drawRect:(CGRect)rect {
    // Drawing code
}
*/

@end
